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Fabrication and Characterization of High-Performance Polymer-Based Magnetoelectric DC Magnetic Field Sensors Devices

2017; Institute of Electrical and Electronics Engineers; Volume: 64; Issue: 6 Linguagem: Inglês

10.1109/tie.2017.2668989

1557-9948

S. Reis, Nélson Castro, M.P. Silva, V. Correia, J. G. Rocha, P. Martins, S. Lanceros‐Méndez,

Acoustic Wave Resonator Technologies

The development of a DC magnetic field sensor based on a magnetoelectric (ME) PVDF/Metglas composite is reported. The ME sensing composite has an electromechanical resonance frequency close to 25.4 kHz, a linear response (r 2 = 0.997) in the 0-2 Oe DC magnetic field range, and a maximum output voltage of 112 mV (ME voltage coefficient α 33 of ≈30 V·cm -1 ·Oe -1 ). By incorporating a charge amplifier, an AC-RMS converter and a microcontroller with an on-chip analog-to-digital converter, the ME voltage response is not distorted, the linearity is maintained, and the ME output voltage increases to 3.3 V (α 33effective = 1000 V·cm -1 ·Oe -1 ). The sensing device, including the readout electronics, has a maximum drift of 0.12 Oe with an average total drift of 0.04 Oe, with a sensitivity of 1.5 V·Oe -1 (15 kV·T -1 ), and a 70 nT resolution. This feature is for the first time reported on a polymer-based ME device and compares favourably with a reference Hall sensor that showed a maximum drift of 0.07 Oe and an average error of 0.16 Oe, 5 V·T -1 sensitivity, and 2 μT resolution. Such properties allied to the accurate measurement of the DC magnetic field (H DC ) in the 0-2 Oe range make this polymer-based device very attractive for applications, such as Earth magnetic field sensing, digital compasses, navigation, and magnetic field anomaly detectors, among others.